车牌图像的局部倾斜畸变校正方法

摘要

In the light of the problem of inclined and distortional Vehicle License Plate(VLP) image that brings adverse effect on subsequence steps of characters segmentation and recognition, this paper proposes an approach based on the local and adaptive scaling techniques to correct inclined Vehicle License Plate(VLP) image.According to the inclined and distortion condition,the method,firstly,divides the VLP image into several parts,and then uses connection point techniques to correct every sub-image and adaptively resizes for the width of every sub-image based on the change of its height.Finally, the corrected sub-images are linked into a whole image.Experiment showes that,using the local technique to correct the inclined and distortion VLP image can obtain better effectiveness than global method.%针对车牌图像的倾斜畸变会对后继字符切割和识别结果带来不利影响的问题,提出使用局部技术和适度缩放技术对车牌图像倾斜畸变进行校正.根据车牌图像不同位置倾斜畸变程度不一样的特点将车牌图像分成若干份;分别对每份图像使用"连接点"法进行倾斜畸变校正,根据字符高度的变化对字符宽度进行同样的缩放;将校正之后的各个子图像连接在一起成为校正之后的车牌图像.实验表明,使用局部法对倾斜畸变车牌图像进行校正的效果要优于使用全局法.